Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, generator, gearbox, nacelle, and a rotor including one or more rotor blades. The rotor blades capture kinetic energy from wind using known foil principles and transmit the kinetic energy through rotational energy to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
During operation, the direction of the wind which powers a wind turbine may change. The wind turbine may thus adjust the nacelle, e.g. through a yaw adjustment about a longitudinal axis of the tower, to maintain alignment with the wind direction. When the yaw angle of the nacelle is adjusted, however, cables extending from the nacelle down through the tower can become twisted. Particularly, when the nacelle is returned to its original position (sometimes referred to as yaw untwisting), the untwisting of the cables can take considerable time, e.g. up to 20 minutes. During yaw untwisting, the wind turbine is not producing power; therefore, time periods of untwisting of the wind turbine can cause considerable energy production loss.
Various attempts have been made to reduce the time it takes for yaw untwisting. For example, some past efforts have involved a static control methodology that operates based on two conditions, including limit switch activation and software control. In either instance, the yaw untwisting operation is triggered after two revolutions, which can still lead to production loss during the operating wind speed range.
Accordingly, improved systems and methods for yaw untwisting so as increase energy production would be welcomed in the art. In particular, systems and methods that provide dynamic yaw control of wind turbines based on wind speed and/or direction so as to reduce the time it takes for yaw untwisting would be desired.